1. Field of the Invention
The present invention relates to a single hung or double hung window, including a side hung (slider) window, that has code meeting egress capabilities without the need for a separate casement system as would be required for a single hung window of the same size.
2. Background of the Prior Art
According to the International Building Code, all bedrooms of a residential dwelling must have egress capabilities directly to the outside of the dwelling in order to allow the occupants in the bedroom to escape immediately to the exterior of the building in case of an emergency such as a fire, and to allow emergency personal to enter the dwelling to rescue any occupants that may still be therein as well as to combat the emergency. Such egress capabilities are typically achieved in one of two manners. One way to achieve code meeting egress is via a door that leads directly to the outside of the dwelling. Barring a door, the other means to achieve egress is via a window that leads directly to the outside of the dwelling. Such a window must meet certain requirements. Under the current International Building Code, an egress window must have all of the following features: 1) the top of the sill cover at the base of the window cannot be more than 44 inches from the floor; 2) the clear space width, the so-called vent space, must be at least 20 inches in width; 3) the clear space height between the top of the sill cover at the base of the window and the bottom of the bottom rail of the upper sash of the window must be at least 24 inches; and 4) the open vent space must be at least 5.7 square feet, this last requirement being the minimum vent spaced needed, in combination with requires 2 and 3, for a firefighter carrying a breathing tank to be able to enter the structure.
In new construction of dwellings, achieving egress is not usually a problem as the architect simply assures that at least one egress point meeting the International Building Code is designed into the dwelling and the contractor assuring that this egress point is actually built according to specifications. The problems occur during remodels of existing dwellings, especially older dwellings that may have been built prior to the adoption of the current International Building Codes or any other code for that matter. Many jurisdictions require that during a remodel, especially a sizable remodel, that each bedroom be brought up to the current International Building Code relating to egress. Some jurisdictions go as far as requiring the bedroom be brought up to code during as simple a procedure as replacing a single window within the bedroom either due to life span fatigue of the existing window or to bring in a more energy efficient window such as replacing a single pane window system with a double pane insulated window system.
If the window or windows being installed are a hung (either a single hung or a double hung) problems often arise as many older structure's bedroom windows have a relatively short height, as such short heights were common in construction techniques decades ago for a variety of reasons. Modern hung windows allow the clear space height of the window to be substantially less than 50 percent of the overall height of the window, despite the fact that the movable sash (or the lower sash in the case of a double hung window) is about 50 percent of the overall window height. This is due to the fact that the meeting rails of the two sashes (the top rail of the lower movable sash and the bottom rail of the upper sash (non-movable if single hung and movable if double hung)) substantially overlap in order to reduce the visual blockage of the meeting rails. As the lower sash is raised to its maximum height, its top rail abuts the head of the window frame, such head reducing travel of the lower sash. In this position, the majority, if not all of the bottom rail of the lower sash is below the bottom rail of the upper sash (if the upper sash is closed in the case of a double hung window). This under hang of the bottom rail of the lower sash below the bottom rail of the upper sash results in the vent space being substantially less than 50 percent of the overall window height. Accordingly, if the egress requirement calls for a clear space height of 24 inches, the overall height of the window must be must greater than 48 inches in order to achieve this clear space.
To address this problem, one of two steps is typically taken, aside from not performing the remodel, which remodel may be required for a variety of reasons. One step is to increase the height of the overall rough opening for the window in order to allow a window with suitable height that will allow the window to achieve the appropriate clear space height needed to comply with egress codes. However, such increase in height tends to be costly. Not only must the window header be raised, which is itself difficult, but the remainder of rough opening that is torn out must also be repaired, which includes both interior and exterior finishing, often requiring a variety of tradesman. Depending on the particular structure involved, increasing the height of the rough opening may not even be feasible at almost any cost.
The other common solution to achieve sufficient clear space height in a hung window is to put a casement feature on the single hung (or double hung) window, so that for code meeting egress, the window functions as a casement window wherein both sashes pivot as a unit about one of the side rails of the window frame (or the top rail of the window frame if the code meeting egress casement is in awning style). Such casement clears out both sashes of the window and gives substantially all of the window height as clear space height in order to meet code. This solution, while widely deployed, has its own problems.
Adding the casement features adds additional structure and thus costs to the window. The knuckles must be installed on each sash (or the top sash if employing an awning style casement) as well as the pivot pin within the knuckles must be provided. If a true casement window style (side pivot) is employed, an additional frame element must be overlaid on one of the side rails of the bottom sash so that the window's knuckles are on the same plane. After the window is installed, other tradesman continue to work at the window site, especially interior finishing tradesman that often bang against the window during normal work, or as is often the case, use the window for egress during work. This often causes the casement portion to go out of balance, requiring the window installer to return after departure of such tradesman to rebalance the window. Additionally, as such casement additions are designed only for egress and not to regularly functional as a casement window, the casement components tend to be inferior in construction in relation to standard casement components that must stand up to regular repeated use. As such, the casement operation of the hung window tends to be a single use feature of the window, to be used only during emergencies. Unfortunately, in many deployments, such as college dormitories, the occupants of the dwelling use the casement feature on a regular basis, even to the point of using the window for ingress and egress (some college parties can get wild) so that the window quickly gets out of square with its frame to the point that the casement portion of the window cannot close, requiring the time and expensive of a service call.
What is needed is a hung window that can be retrofitted into an existing window opening during window replacement, which hung window meets the clear space height requirements for egress of the applicable code, wherein a prior art window does not achieve the clear space height. Such a hung window must not rely on a secondary window opening system so as to reduce the overall costs of the window manufacture and after installation maintenance and must be relatively straightforward to install.